Exercise apparatus



May 12, 1970 G. CORWIN EXERCISE APPARATUS 5 Sheets-Sheet 1 Filed Sept. 29, 1967 FUSE 70 METER\ COUNTER J (7" EASY HARD INVENTOR. GILBERT CORWIN ATTORNEYS.

May 12, 1970 G. CORWIN 3,511,097

EXERCISE APPARATUS Filed Sept. 29. 1967 3 Sheets-Sheet 2 FIG-.4

May 12, 1970 G. CORWIN EXERCISE APPARATUS 3 Sheets-Sheet 5 Filed Sept. 29, 1967 ,v INVENTOR. g GlLBERT CORWIN ATTORNEYS.

United States Patent 3,511,097 EXERCISE APPARATUS Gilbert Corwin, 2403 Elmwood Drive, Westlake, Ohio 44145 Filed Sept. 29, 1967, Ser. No. 671,853 Int. Cl. G011 /02 US. Cl. 73-379 26 Claims ABSTRACT OF THE DISCLOSURE The apparatus comprises a bicycle-like device, which is pedalled by a person using the apparatus. Pedalling rotates the armature of a generator, and the output of the generator energizes electronic circuitry. Means are provided in the circuitry for indicating the rate at which food calories are being expended, as well as means for indicating the total number of food calories expended as an exercise period progresses. The electronic circuitry includes two current integrators with means for re-cycling the integrators to provide the two output indications.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to exercise apparatus, and, more particularly, to such apparatus embodying electronic circuitry for indicating the rate at which food calories are being expended by a user, as well as means for indicating a cumulative total of food calories expended as an exercise period progresses.

Discussion of the prior art Various devices have been proposed heretofore that have measured in one fashion or another the energy expended by a user. Most of these devices have been applicable to medical applications, where a patient must exert a certain, predetermined amount of energy, while undergoing diagnostic examinations such as the making of electrocardiograms, etc. In such an application, there is no need for precisely determining the rate at which energy is being expended or the total amount of energy expended at any given time after the start of the program. It has been suflicient merely to know that at least a certain amount of energy is being expended.

In another known device of this general type, a patient mechanically rotates a generator of a motor-generator unit. The motor is caused to rotate at a desired speed by electrical energization, and the patient is instructed to rotate the generator at the same speed as the motor. The output of the generator is read on a watt meter. As the rotational speed of the motor is reduced by reducing its electrical energization, the patient must exert more energy to maintain the original rotational speed of the motor. Such additional energy expended by the patient can be measured by the Watt meter.

In still another device, means are provided for indicating the amount of human energy delivered to the device in a certain interval of time. Integrating means are provided for obtaining a measure of the cumulative energy delivered to the work load, such a measure being provided by a digit wheel counter. Means are also provided for giving a very general indication of the rate at which work is being performed. The entire apparatus is strictly mechanical in nature, however, and so is subject to the inaccuracies and breakdown problems inherent in such mechanical apparatus.

Accordingly, it is a general object of the present invention to provide exercise apparatus, in which the rate at which food calories are being expended by a user "ice is precisely indicated and in which the cumulative total of food calories expended is also precisely indicated.

It is another general object of the invention to provide exercise apparatus, in which the measuring and indications means are entirely electronic in nature and preferably comprise solid state devices rather than electron discharge devices.

SUMMARY OF THE INVENTION A user of apparatus embodying the invention sits on a bicycle-like stand and rotates the armature of an electric generator mechanically coupled to pedals of the apparatus. The output of current of the generator passes through a load resistor, the voltage across which is provided to a first integrating circuit. The output of the first integrating circuit energizes a first pulse generator, which produces a first series of pulses at a rate proportional to the voltage across the generator load resistor. These pulses along with the generator load voltage are supplied to circuitry that provides an output current proportional to the power delivered by the generator. This current is converted into units of food calories being expended and indicated on a meter.

The signal that energizes the aforementioned meter is also used to operate a second integrating circuit to provide a second series of pulses whose rate is a function of the generator power output. Each output pulse of the second series represents a unit of power delivered to the load, and, by proper adjustment of circuit constants, can be made equal to a desired number of food calories or fraction of a food calorie. The second series of pulses is utilized to actuate a counter to indicate a cumulative total of food calories expended since the start of an exercise period.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of exercise apparatus em bodying the invention;

FIG. 2 is an elevational view of the apparatus of FIG. 1;

FIG. 3 is a plan view of the indicator and control panel shown in FIG. 1 and taken on the line 33 of FIG. 2;

FIG. 4 is a block diagram of the electronic portion of the apparatus; and

FIG. 5 is a schematic diagram of the electronic portion shown in block diagram form in FIG. 4.

DESCRIPTION OF A PREFERRED EMBODIMENT As shown in FIGS. 1 and 2, exercise apparatus enibodying the invention comprises a stationary bicyclelike stand 10 having rear feet 12 and a front fork 14 resting on front feet 16. The stand supports a bicycle seat 18 on which a user 20 of the apparatus sits and holds handlebars 22. The stand 10 is also provided with conventional bicycle pedals 24, which are keyed or otherwise secured to a shaft 26 rotatably mounted in bearings (not shown) in the frame. A sprocket wheel 28 is mounted on the shaft 26 for rotation with the shaft, and drives a conventional link chain 30. The chain 30 engages and drives another sprocket wheel 32, which is mounted on and rotates a shaft 34. The shaft 34 is mounted for free rotation in conventional bearings 36 supported in a U-shaped bracket 38 that is welded or otherwise secured to the front fork 14 of the stand 10 and extends rearwardly from the fork.

A V-pulley 40 is also mounted for rotation with the shaft 34, and drives a smaller V-pulley 42 by means of a belt 44. The V-pulley 42 is secured to a rotatable armature shaft 46 of an electrical generator 48. The generator 48 is provided with two pairs of lugs 50, 52. Each of the upper lugs 50 is pivotally secured between the ends of a strap 54 that encircles one of the legs of the fork 14. The weight of the generator is supported by the upper lugs 50 and straps 54. Some movement of the pulley 42 toward and away from the pulley 40 is required in order to change the belt 44 and to adjust the belt tension. This movement is provided by a pair of straps 56, each of which encircles a leg of the fork 14, and may be adjusted upwardly and downwardly on a respective leg of the fork. A pair of rods 58 are provided, each of which has one end retained by a respective strap for limited pivotal movement about a horizontal axis, and another end secured in a lug 52 for pivotal movement about a horizontal axis. Thus, as the straps 56 are moved upwardly and downwardly on the fork 14, the generator 48 will pivot about a horizontal axis defined by the pivotal connections of the lugs 50 to the straps 54. This motion of the generator permits increasing and decreasing the tension on the belt 44 connecting the pulleys 40, 42.

The electronic circuitry embodied in apparatus of the invention is completely contained within a case 60, which is secured to the front fork 14 by means of straps 62. A portion of the case 60 may be removable to permit access to the electronics for testing and maintenance purposes.

The case 60 has a top panel 64 within easy view of a user of the apparatus, which panel is shown in FIG. 3. The top panel 64 has mounted thereon an ON-OFF switch 66, an ON- OFF indicator light 68, and a fuse 70. It also has a knob 72 for adjusting the excitation of the field winding of the generator, thereby to adjust the mechanical resistance to pedalling and rotating the generator. In other words, the less field excitation, the less the energy required to turn the generator armature and the less the output voltage from the armature. Of course, the converse is also true.

A meter 74 and a numerical counter 76 are also mounted on the top panel 64. The meter 74 may be calibrated in food calories to indicate the rate at which such calories are being expended. The counter 76 'has a dial 76A that indicates the cumulative total of food calories (or multiples of units of food calories) expended since the start of an exercise period. The counter 76 has a knurled RESET wheel 76B for re-setting the counter dial to zero at the start of an exercise period.

FIG. 4 is a block diagram of the electronic portion of apparatus embodying the invention. As shown schematically, the pedals 24 mechanically drive the armature of the generator 48 to produce an output votlage across a fixed load resistor 80. The voltage appearing across the load resistor 80 is provided to an integrating amplifier 81 comprising an input resistor 82, an operational amplifier 84, and a feedback capacitor 86. The amplifier 84 is of conventional commercial design and availability; a suitable amplifier is available from Motorola Inc., Chicago, Ill., and is known as Model MC 1709 CG, although certainly the invention is not limited to the use of any particular amplifier.

It will be helpful at this point to consider the basic definitions on which the utility of the present invention is predicated. First, a food calorie (or large calorie) is equal to a kilogram-calorie, or 4183 joules. Second, an electrical load absorbing approximately 70 watts for one minute has absorbed 4200 joules, or approximately one kilogramcalorie. Thus, the rate at which power is absorbed by an electrical load can be used as a measure of the rate at which food calories are being expended, and the cumulative total of power absorbed is a measure of the cumulative total of food calories expended in a given period. The rate at which power is absorbed by the electrical load is proportional to the square of the voltage drop across the load (E and the integral of that quantity with respect to time is proportional to cumulative power absorbed.

As shown in FIG. 4, the operational amplifier 84 is provided with the feedback capacitor 86, which integrates the current flowing through the resistor 82 into the amplifier. The output of the amplifier 84 is connected to the input of a pulse generator 88 comprising a Schmitt trigger circuit, a monostable multivibrator and an output buffer amplifier, the latter components not being individually shown in FIG. 4. So far as the block diagram is concerned, it is sufficient to note that as a charge accumulates across the capacitor 86, the output of the amplifier 84 changes. When the output of the amplifier has reached a predetermined level, the Schmitt trigger in the pulse generator '88 is actuated, which, in turn, actuates the monostable multivibrator to produce a first pulse of predetermined width. This pulse is buffered by the buffer amplifier in the pulse generator 88, and then provided as a positive pulse to an output amplifier 90.

A negative output pulse from the amplifier 90 is provided to a charge pump circuit 94 connected to the input of the integrating amplifier 81. The negative pulse supplied from the amplifier 90 to the charge pump 94 causes the capacitor 86 to discharge by an amount sufficient to de-actuate the Schmitt trigger and reset it. This cyclic action will continue so long as there is current flow into the integrating amplifier 81. Because the amount of charge pumped away for each cycle is the same, the repetition rate of the output pulses from the output amplifier 90 is a function of the voltage app ied across the load resistor from the generator 48.

The output of the amplifier is also supplied to one input of a voltage amplitude gate 98. A second input signal is provided to the gate 98 from across the load resistor 80. The voltage amplitude gate 98 comprises a driver and a power transistor, with the output of the power transistor being a first series of pulses whose repetition rate is directly proportional to the voltage developed across the generator load resistor 80, and whose amplitudes are similarly direct y proportional to the generator load voltage.

The first series of pulses provided from the amplitude gate 98 is used for two purposes. First, the pulses are utilized to energize a meter 100 connected across a calibrating variable resistor 101, which meter indicates the rate at which food calories are being expended. Second, they are provided through a charge pump to a second integrator and charge pump to provide a second series of pulses whose repetition rate is a function of the generator power output. The first series of pulses is applied to the meter 100 through a charge pump 102, and is applied through a charge pump 104 to an integrating amplifier 105 comprising an operational amplifier 106, an input resistor 107, and a feedback capacitor 108. In both cases, the charge transferred through the charge pumps 102, 104 is proportional to the square of the voltage drop across the load resistor 80 and hence is proportional to the power being delivered by the generator 48 (assuming that the resistor 80 is fixed in value).

The integrating amplifier 105 and the succeeding circuits operate in essentially the same fashion as those previously described. The operational amplifier 106 is provided with the integrating feedback capacitor 108, and the output of the amplifier 106 modified by the charge built up across the capacitor 108 is supplied to a pulse generator 110. The pulse generator 110 comprises a Schmitt trigger, a monostable multivibrator, and a buffer amplifier, like the pulse generator 88 previously described. An output amplifier 112 receives the output of the pulse generator 110, and the output of the amplifier 112 actuates a charge pump 114 connected to the input of the integrating amplifier 105. Thus, the output of the amplifier 112, which is supplied to a driver amplifier 116, is a second series of pulses whose repetition rate is a function of the generator power output. By proper selection of circuit constants, each pulse of the second series of pulses can be made to represent a desired multiple (fractional or integral) of a food calorie. It has been found in practice that a convenient multiplier is 0.1, so that each pulse represents 418.3 watt seconds.

The second series of pulses, amplified by the amplifier 116, is used to drive a conventional electromagnetic counter 118, which registers one count for each pulse received. Thus, the reading of the counter 118 indicates at any time the cumulative total of food calories expended since the counter was reset at zero.

FIG. is a schematic diagram of the circuitry shown in block diagram form in FIG. 4. A lead 120 connects the generator load resistor 80 (FIG. 4) through a fixed resistor 122 and a variable resistor 124 to the input of the operational amplifier '84 in the integrating amplifier 81. A capacitor 126 connects the lead 120 to ground. Positive and negative operating potentials are supplied to the amplifier 84 and to the other circuit components from lines 128, 130 respectively connected to +6 volt and 6 volt supplies (not shown). The +6 volt and 6 volt power supplies are conventional and are energized from a conventional 110 volt alternating current household source.

The integrating capacitor 86 is connected between an inverting input terminal and the output of the amplifier 84. Current flows through the resistors 122, 124 and into the capacitor 86. As a positive charge accumulates on the plate of the capacitor 86, the amplifier output appearing across a resistor 132 becomes increasingly negative. The resistor 132 is connected between the amplifier output and the 6 volt line 130. Leakage current compensation that is required for accuracy is supplied to the input of the amplifier 84 through a resistor 134 from a movable arm of a potentiometer 136 connected between the +6 volt line 128 and ground.

The output voltage of the amplifier 84 is provided through a resistor 138 to the base of an NPN transistor 140. The transistor 140 and another NPN transistor 142 comprise the Schmitt trigger which is part of the pulse generator 88 as previously mentioned. The collector of the transistor 140 is connected to the line 128 through a load resistor 144, and to the base of the transistor 142 through a parallel combination of a resistor 146 and a capacitor 148. The base of the transistor 142 is connected to the 6 volt line 130 through a resistor 150. The emitters of the transistors 140, 142 are connected together and to the line 130 through a resistor -152. The collector of the transistor 142 is connected to the +6 volt line 128 through a road resistor 154. The output of the Schmitt trigger is taken across a resisor 156, one end of which is connected to the line 130 and the other end of which is connected through a capacitor 158 to the collector of the transistor 142.

The negative output of the Schmitt trigger is differentiated by the resistor 156 and the capacitor 158 and is coupled through a diode 160 to the base of an NPN transistor 162. The transistor 162 and a second NPN transistor 164 comprise the monostable multivibrator previously referred to as being a part of the pulse generator 88. The base of the transistor I162 is connected through a resistor 166 to the negative line 130 and through a resistor 168 to the positive line 128. The collector of the transistor 162 is connected to the line 128 through a load resistor 170. The emitters of the transistors 162, 164 are connected together and to the line 130 through a resistor 172. The collector of the transistor 164 is connected through a load resistor 174 to the line 128 Interaction between the transistors 162, 164 is accomplished by connecting the base of the transistor 162 to the collector of the transistor 164 through a capacitor 176, and by connecting the base of the transistor 164 to the collector of the transistor 162 through a parallel combinaion of a resistor 180 and a capacitor 182. The base of the transistor 164 is also connected to the line 130 through a resistor 178. base of an NPN transistor 184 through a resistor 186. The

The collector of the transistor 162 is connected to the base of the transistor 184, which serves as the buffer amplifier 90, is also connected to the line 130 through a resistor 188. The collector of the transistor 184 is connected directly to the positive line 128, and the transistor emitter is connected to the negative line 130 through a resistor 190. The positive output of the transistor I184 is taken from its emitter and supplied through a diode 192 and a resistor 194 to the base of an NPN transistor 196. The emitter of the transistor 196 is connected directly to the negative line 130 and through a potentiometer 198 to the positive line 128. A movable arm on the potentiometer 198 is connected to the collector of the transistor 196. The collecor of the transistor 196 is also connected directly to the charge pump 94.

The charge pump 94 comprises a pair of diodes 200, 202 connected in series to ground and the transistor 196. The charge pump 94 also includes a capacitor 204 having one side connected to the juncture of the diodes 200, 202 and another side connected directly to the collector of the transistor 196. The operation of the charge pump will be described later in connection with the operation of the overall circuit of which it is a part.

As previously mentioned, the voltage amplitude gate 98 receives input signals from the output of the pulse generator 88 and from the generator load resistor .(FIG. 4). As shown in FIG. 5, the amplitude gate comprises an NPN transistor 206 and a PNP transistor 208. The base of the transistor 206 is connected through a resistor 210 to the juncture of the diode 192 and the resistor 194 in the buffer amplifier 184 to receive one input signal, and the emitter of the transistor 208 is connected to a lead 212 that is in turn connected to the input lead 120. The collector of the transistor 206 and the base of the transistor 208 are connected together and to the lead 212 through a resistor 214. The emitter of the transistor 206 is connected to the line 130 through a load resistor 215. The collector of the transistor 208 is connected to ground through a load resistor 216.

The output of the gate 98 is taken from across the load resistor 216 and applied to the charge pumps 102, 104. The charge pump 102 comprises a capacitor 218 having one side connected to the collector of the transistor 208 (and hence, to the top of the load resistor 216) and its other side connected to the cathode of a diode 220. The anode of the diode 220 is connected to the grounded side of the resistor 216. The juncture of the capacitor 218 and the diode 220 is connected to the anode of a diode 222, whose cathode is connected through the meter and parallel resistor 101 to ground. A filter or integrating capacitor 224 is connected across the meter 100.

The charge pump 104 comprises a capacitor 226 having one side connected to the collector of the transistor 208 and its other side connected to the cathode of a diode 228. The anode of the diode is grounded. The juncture between the capacitor 226 and the diode 228 is connected to the anode of a diode 230; the cathode of the diode 230 is connected to ground through a filter or integrating capacitor 232. The juncture between the diode 230 and the capacitor 232 is connected through the input resistor 107 to the input of the operational amplifier 106 and to the integrating capacitor 108 in the integrating amplifier 105.

The portion of the electronic circuitry shown in the lower half of FIG. 5 is, except for its output components and connections, similar to the circuitry shown in the upper half of the figure. Therefore, those components appearing to the right of the integrating amplifier that correspond to components shown in the upper half of the figure are designated by the same reference numerals with prime sufiixes. It is believed that the various connections of this portion of the circuitry will be apparent without a detailed explanation.

The output of the amplifier 112 in the lower portion of the circuitry is supplied to the driver amplifier 116 for energizing the actuating coil of the electromagnetic counter 118. The driver amplifier 116 comprises an NPN transistor 234 and a PNP transistor 236. The base of the transistor 234 is connected to receive the output signal of the amplifier 112 through a resistor 210'. The emitter of the transistor 234 is connected to the negative line 130' through a resistor 238. The collector of the transistor 234 is connected directly to the base of the transistor 236 and to a source of +18 volts through a load resistor 240. The emitter of the transistor 236 is connected directly to the +18 volt source, and the transistor collector is connected through the actuating coil of the counter 118 to the negative supply line 130'.

The +18 volt power supply is conventional and it, in combination with the -6 volt supply, provides 24 volts to actuate the coil of the counter 118.

When operation is initiated, or immediately after the integrating amplifier 81 has been recycled, the output voltage of the operational amplifier 84 is essentially at zero volts. This voltage transferred to the base of the transistor 140 in the Schmitt trigger circuit causes the transistor 140 to conduct, thus drawing current through and causing a voltage drop across the resistor 144 in its collector circuit. Thus, the voltage applied to the base of the transistor 142 in the Schmitt trigger circuit is less than the voltage at the emitter of the transistor, and the transistor 142 is in a non-conducting state. During operation, as the voltage at the base of the transistor 140 becomes increasingly negative, the transistor 140 remains in a conductive state until its base bias voltage becomes less than the potential on its emitter. When this occurs, the transisor 140 ceases conducting and the voltage at its collector rises sharply. This voltage rise is transferred to the base of the transistor 142 through the capacitor I148, thus causing the transistor 142 to become conductive. Conduction through the transistor 142 is maintained by the increased base voltage now available through the resistor 146. When the transistor 142 conducts, a negative signal appears across the resistor 154 in its col ector circuit, which signal is differentiated by the resistor 156 and the capacitor 158 to apply a negative pulse through the diode 160 to the base of the transistor 162.

The transistors 162, 164 with their associated circuit elements comprise the monostable multivibrator previously mentioned in connection with the block diagram of FIG. 4. The base of the transistor 162 is so biased by current flow through the resistors 166, 168 that the transistor 162 is in a conductive state. The transistor 164 is maintained in a non-conductive state because of the relatively low voltage transferred to its base through the resistor 180 from the collector of the transistor 162. When a negative pulse is applied to the base of the transistor 162, the transistor is momentarily driven to a non-conductive state and the voltage at its collector rises sharply. 'Ihis positive rise is transferred to the base of the transistor 164 through the capacitor 182, thus causing the transistor 164 to conduct and Causing the voltage at its collector to drop sharply. This voltage drop is transferred to the base of the transistor 162 through the capacitor 176 to maintain the transistor 162 in a non-conductive state until the capacitor 176 is discharged by current flow through the resistor 168. When the capacitor 176 has discharged, the transistor 162 is again biased to a conductive state, which in turn biases the transistor 164 to a non:- conductive state. Thus, there is a single positive pulse at the collector of the transistor 162 each time the base of the transistor 140 in the Schmitt trigger is driven negative The time duration or width of the positive pulse is determined =by the time constant of the resistor 168 and capacitor 17 6 in the capacitor discharge circuit.

The positive pulse occurring at the collector of the transistor 162 is transferred through the conventional buffer amplifier transistor 184 to the bases of the transistors 196, 206. The diode 192 connected between the emitter of the transistor 184 and the bases of the transistors 196, 206 has a slight forward voltage drop that serves to reduce the voltage at the bases of the transistors 196, 206 and insures that they will conduct only during a positive excursion of the voltage appearing at the collector of the 8 transistor 162. When the transistor 196 conducts in response to a positive pulse appearing on its base, a negative pulse appears at its collector. This negative pulse is applied to the capacitor 204 in the charge pump 94 connected to the input of the integrating amplifier 81.

When the negative pulse from the collector of the transistor 196 appears on one side of the capacitor 204, it is neutralized by current flowing from the integrating capacitor 86 through the diode 200. When the voltage at the collector of the transistor 196 again rises to its original value at the termination of the input pulse to its base, the charge that has come from the integrating capacitor 86 is conducted to ground through the diode 202. The movable arm of the potentiometer 198 is so adjusted that the charge required from the capacitor 86 to neutralize the negative pulse transmitted to the capacitor 204 is just sufficient to restore the output voltage from the integrating amplifier 81 to its initial value and reset the Schmitt trigger circuit.

The positive pulse from the collector of the transistor 162 and from the emitter of the transistor 184 is also applied to the base of the driver transistor 206. The collector voltage of the transistor 206 and the emitter voltage of the transistor 208 are both obtained from the lead 212 which is connected to the generator load resistor shown in FIG. 4. When a positive pulse is applied to the base of the transistor 206, the transistor 206 conducts thus applying a negative voltage to the base of the transistor 208. When the transistor 208 saturates, the voltage pulse appearing at its collector closely approximates the value of the voltage appearing across the generator load resistor 80, because there is very little emitter-collector voltage drop across the transistor. These positive pulses appearing at the collector of the transistor 208 are applied to the charge pump circuits 102, 104.

The charge pump 102 comprises the capacitor 218 and the diodes 220, 222. When a positive output pulse appears on the collector of the transistor 208, it places a positive charge on the upper plate of the capacitor 218. Thus current flows through the diode 222 and the meter to ground. At the termination of the positive output pulse from the transistor 208, current flows from ground to the lower plate of the capacitor 218 through the diode 220. The capacitor 224 serves to integrate or smooth the pulsating current applied to the meter. The charge transferred through the charge pump 102 is determined by the amplitudes of the pulses apearing at the collector of the transistor 208 and the pulse repetition rate of the pulses. Inasmuch as both of these quantities are proportional to the generator load voltage, the total charge transferred is proportional to their product (E and thus is proportional to the power delivered by the generator to the load resistor.

The charge pump 104 comprises the capacitor 226, and the diodes 228, 230. It operates in the same fashion as the charge pump 102 previously described, and functions to transfer to the integrating amplifier 105 a charge that is proportional to the power delivered by the generator 48 to its load resistor 80 (FIG. 4).

The integrating amplifier 105 comprises the resistor 107, the operational amplifier 106, and the feedback capacitor 108. The transistor 142' form a Schmitt trigger circuit similar to that formed by the transistors 140, 142 previously described, and the transistors 162, 164' form a monostable multivibrator similar to that formed by the transistors 162, 164 previously described. The transistor 184' comprises the buffer amplifier 112, and the transistor 196' is a part of the charge pump 114 connected to the input of the integrating amplifier 105. The buffer amplifier 184' provides on its emitter a second series of pulses, each pulse of which represents a unit quantity of power delivered. By proper adjustment of the various circuit constants, this unit quantity of power delivered can be made equal to 0.1 of a food calorie or any other desired multiple of a food calorie.

The principal difference between the circuitry shown in the upper half of FIG. and that shown in the lower half of the figure lies in the output stage comprising an NPN transistor 234 and a PNP transistor 236. The base of the transistor 234 receives positive pulses from the emitter of the transistor 184'. The transistor 234 acts as a driver transistor and conducts heavily in response to the positive pulses applied to its base. This results in negative pulses being applied from its collector to the base of the power transistor 236. The actuating coil for the counter 118 is connected in the collector circuit of the power transistor 236, and hence is energized by each positive pulse transmitted to the output circuitry from the buffer transistor 184. Thus, the counter 118 is caused to register each pulse received to indicate a cumulative total of multiples of food calories expended since the counter 118 was reset to its zero or starting position.

It is now apparent that apparatus embodying the invention provides an accurate indication of the rate at which food calories are being expended by a user of the appara tus, as well as an accurate indication of the cumulative total of food calories expended by the user since the start of an exercise period. Although an embodiment of the invention has been shown and described in detail, it is apparent that many changes and modifications may be made by one skilled in the art without departing from the true spirit and scope of the invention.

What is claimed is:

1. Apparatus for indicating energy expended and work done by an individual comprising:

(a) electrical generator means to be mechanically driven by said individual for providing a generator output voltage;

(b) first means for receiving said generator output voltage and providing a first series of pulses having a repetition rate substantially proportional to amplitude of said generator output voltage and pulse amplitudes proportional to said amplitude of said generator output voltage;

(c) second means for receiving said first series of pulses and providing a second series of pulses having a second repetition rate substantially proportional to a square of said generator output voltage amplitude; and

((1) counter means for receiving said series of second pulses and providing an indication of number of pulses received.

2. The apparatus of claim 1, further including indicator means for providing an indication of said first repetition rate.

3-. The apparatus of claim 1, wherein said counter means is calibrated in terms of cumulative food calories expended by said individual.

4. The apparatus of claim 2, wherein said indicator means is calibrated in terms of a rate at which food calories are being expended by said individual.

5. The apparatus of claim 2, wherein said indicator means is calibrated in terms of a rate at which food calories are being expended by said individual and said counter means is calibrated in terms of cumulative food calories expended by said individual.

6. The apparatus of claim 1, wherein said first means comprises:

(i) first integrating means for receiving said generator output voltage and producing a first output signal whose amplitude is proportional to a time integral of said generator output voltage;

(ii) first pulse generator means for receiving said first output signal and producing a first pulse output signal of predetermined width when said amplitude of said first output signal reaches a predetermined level;

(iii) first cycling means for re-cycling said first integrating means in response to each said first pulse output signal, and

(iv) amplitude gate means for receiving said first pulse output signal and said generator output voltage and producing said first series of pulses.

7. The apparatus of claim 1, wherein said second means comprises:

(i) second integrating means for receiving said first series of pulses and producing a second output signal whose amplitude is proportional to a time integral of said first series of pulses;

(ii) second pulse generator means for receiving said second output signal and producing a second pulse output signal of predetermined width when said amplitude of said second output signal reaches a predetermined level; and

(iii) second cycling means for recycling said second integrating means in response to each said second pulse output signal for producing said second series of pulses.

8. The apparatus of claim 1, wherein said first means comprises:

(i) first integrating means for receiving said generator output voltage and producing a first output signal 'whose amplitude is proportional to a time integral of said generator output voltage;

(ii) first pulse generator means for receiving said first output signal and producing a first pulse output signal of predetermined Width when said amplitude pf said first output signal reaches a predetermined evel;

(iii) first cycling means for recycling said first integrating means in response to each said first pulse output signal, and

(iv) amplitude gate means for receiving said first pulse output signal and said generator output voltage and producing said first series of pulses;

and said second means comprises:

(i) second integrating means for receiving said first series of pulses and producing a second output signal whose amplitude is proportional to a time integral of said first series of pulses;

(ii) second pulse generator means for receiving said second output signal and producing a second pulse output signal of predetermined width when said amplitude of said second output signal reaches a predetermined level; and

(iii) second cycling means for recycling said second integrating means in response to each said second pulse output signal for producing said second series of pulses.

9. The apparatus of claim 6, wherein said first pulse generator means comprises a Schmitt trigger circuit and a monostable multivibrator connected in series.

10. The apparatus of claim 7, wherein said second pulse generator means comprises a Schmitt trigger circuit and a monostable multivibrator connected in series.

11. The apparatus of claim 6, further including indicator means for providing an indication of said first repetition rate.

12. The apparatus of claim 11, wherein said indicator is calibrated in terms of a rate at which food calories are being expended by said individual.

13. The apparatus of claim 11, wherein said indicator means is calibrated in terms of a rate at which food calories are being expended by said individual and said counter means is calibrated in terms of cumulative food calories expended by said individual.

14. The apparatus of claim 7, further including indicator means for providing an indication of said first repetition rate.

15. The apparatus of claim 14, Nvherein said indicator means is calibrated in terms of a rate at which food calories are being expended by said individual.

16. The apparatus of claim 14, wherein said indicator means is calibrated in terms of a rate at which food calories are being expended by said individual and said :ounter means is calibrated in terms of cumulative food calories expended by said individual.

17. The apparatus of claim 8, further including indicator means for providing an indication of said first repetition rate.

18. The apparatus of claim 17, wherein said indicator means is calibrated in terms of a rate at which food calories are being expended by said individual and said :ounter means is calibrated in terms of cumulative food :alories expended by said individual.

19. Apparatus for converting an input voltage developed across an impedance to power dissipated in terms of watt-seconds comprising:

(a) first integrating means for receiving said input voltage and producing a first output signal whose amplitude is proportional to a time integral of said input voltage;

(b) first pulse generator means for receiving said first output signal and producing a first pulse output signal of predetermined width when said amplitude of said first output signal reaches a predetermined level;

(c) first cycling means for recycling said first integrating means in response to each said first pulse output signal;

(d) amplitude gate means for receiving said first pulse output signal and said generator output voltage and producing a first series of pulses having a first repetition rate substantially proportional to amplitude of said input voltage and pulse amplitudes substantially proportional to said amplitude of said input voltage;

(e) second integrating means for receiving said first series of pulses and producing a second output signal whose amplitude is proportional to a time integral of said first series of pulses;

(f) second pulse generator means for receiving said second output signal and producing a second pulse output signal of predetermined Width when said amplitude of said second output signal reaches a predetermined level; and

(g) second cycling means for recycling said second integrating means in response to each said second pulse output signal for producing a second series of pulses having a second repetition rate substantially proportional to a square of said input voltage amplitude.

20. The apparatus of claim 19, further including counter means for receiving said second series of pulses and providing an indication of number of pulses received.

21. The apparatus of claim 19, wherein said first pulse generator means comprises a Schmitt trigger circuit and a monostable multivibrator connected in series.

22. The apparatus of claim 19, wherein said second pulse generator means comprises a Schmitt trigger circuit and a monostable multivibrator connected in series.

23. The apparatus of claim 19, further including indicator means for providing an indication of said first repetition rate.

24. The apparatus of claim 20, further including indicator means for providing an indication of said first repetition rate.

25. Apparatus for indicating energy expended by an individual comprising:

(a) electrical generator means to be mechanically driven by said individual for providing a generator output voltage;

(b) means responsive to said generator output voltage for providing a series of pulses having a repetition rate substantially proportional to amplitude of said generator output voltage comprising:

(i) integrating means responsive to said generator output voltage producing an output signal whose amplitude is proportional to a time integral of said generator output voltage;

(ii) pulse generator means responsive to said output signal for producing a pulse output signal of predetermined Width when said amplitude of said output signal reaches a predetermined level;

(iii) cycling means for re-cycling said integrating means in response to each said pulse output signal; and

(iv) amplitude gate means responsive to said pulse output signal and to said generator output voltage for producing said series of pulses;

(c) indicator means responsive to said series of pulses for providing an indication of said repetition rate.

26. The apparatus of claim 25, wherein said pulse generator means comprises a Schmitt trigger circuit and a monostable multivibrator connected in series.

References Cited UNITED STATES PATENTS 3,057,201 10/1962 Jaeger 73-379 3,060,388 10/1962 Ball ct al. 3329 3,192,772 7/1965 Tarter 73379 3,375,717 4/1968 Impellizzeri et al. 73-379 RICHARD C. QUEISSER, Primary Examiner E. I. KOCH, Assistant Examiner US. Cl. X.R.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent NO. Dated y 0 Invent r( It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, line 47, "votlage" should be ---voltage--.

Column 5. line 72. an unrelated phrase has been inserted.

Column 6, line 11, "collecor" should be --collector--- SIGNED m ssmn AUG25197O (SEAL) mm x. m. Aneating Officcr commissioner at meats ORM PO-IOSO (10-69) uscoMM-DC GOSH-P69 ll S GOVERNMENT PRINTING OFHC! "l9 O-Jl-SSI 

